1. Technical Field
The present invention relates to a μ-polyoxo crosslinked phthalocyanine compound, a preparing method thereof, and a near infrared ray absorbing and reflecting composition using the same, and more particularly, to a μ-polyoxo crosslinked phthalocyanine compound having high absorption at a wavelength of 800 to 950 nm and high reflectance at a wavelength of 1200 nm or more, a preparing method of a μ-polyoxo crosslinked phthalocyanine compound simultaneously having these near infrared ray absorption and reflection properties, and a near infrared ray absorbing and reflecting composition using the μ-polyoxo crosslinked phthalocyanine compound.
2. Description of the Related Art
The present invention relates to a novel μ-polyoxo crosslinked phthalocyanine compound and applications of a near infrared ray absorbing and reflecting composition using the same. An organic dye or pigment according to the related art has been widely used as a colorant, and particularly, some of the phthalocyanine based dyes have been widely used in an optical information recording medium field. These recording media in which data written once may be repeatedly read are referred to as write once read many (abbreviated as “WORM”). As an example of a disk format using this technology, a compact disk recordable, or so-called CD-R has been known at “Optical Data Storage 1989”, Technical Digest Series, Vol. 1 45 (1989).
Among all of the organic dyes for optical recording medium, a phthalocyanine compound is one of the most important categories due to high absorption in a near infrared ray range (700 to 900 nm). As compared to other organic dyes such as cyanine, the phthalocyanine dye has more excellent light resistance, temperature resistance, and moisture resistance.
Phthalocyanine compounds were disclosed as a constituent component of a record layer of an optical recording medium in the initial documents such as JP-A 154888 (1986), 197280 (1986), 246091 (1986), U.S. Pat. No. 4,769,307 (1987), and JP-A 39388 (1988). However, the phthalocyanine compounds of the above-mentioned documents may not be considered as a suitable material for an optical recording medium in view of sensitivity, solubility, recording performance, and other related properties.
In order to overcome the above-mentioned disadvantages associated with the phthalocyanine compound used as an optical recording material, phthalocyanine compounds having a larger substituent (having a larger steric hindrance effect) in a phenyl ring were provided in JP-A 62878 (1991). However, these materials were not suitable for a recording material. A phenyl-substituted phthalocyanine (also, referred to as naphthalocyanine) dye was suggested in U.S. Pat. No. 5,229,507 (1993), but solubility of this dye was insufficient. The dye sometimes precipitates during spin-coating under predetermined process conditions.
A solubility issue was described in U.S. Pat. No. 5,641,879 (1997) by introducing various large substituents in a phenyl ring of phthalocyanine. However, inappropriate reflectance was observed. An effect of an isomer on solubility was studied in U.S. Pat. No. 5,663,326. It was reported that in order to obtain the desired solubility, a composition of two isomers having a pair of alkoxy substituents facing each other should be 80% or more. It is obviously unpractical to accurately control the composition of the isomer for quality management in preparing process of a dye.
A phthalocyanine compound in which a metal is introduced as a central atom has been disclosed in Korean Patent Laid-Open Publication Nos. 2003-96052 and 2005-20832, but it was confirmed that in the above-mentioned phthalocyanine compound, which is a single metal phthalocyanine compound or oxo crosslinked a different kind—metal phthalocyanine compound, mostly, near infrared ray absorption only at 800 nm or less was low, and properties such as light fastness, thermal stability, dispersibility, chemical resistance, solvent resistance, and the like, were weak. Further, in the case of mixing the single metal phthalocyanine compound or oxo crosslinked a different kind—metal phthalocyanine compound with a generally used color pigment and using the mixture, there is a disadvantage in that since it is difficult to clearly distinguish absorption spectra of near infrared ray absorber and the color pigment from each other due to an overlapping phenomenon of an absorption wavelength, various colors were not obtained. Furthermore, in the case of using carbon black or graphite, only a dark or black color was provided, such that it was difficult to exhibit various colors. Therefore, there is a disadvantage in that forgery or falsification may be easily performed.